“She hasn’t had any retching with me and she’s been sleeping on and off.”

The Aussie DJs even got fellow radio staff to pretend to be the Queen’s corgis by barking.

The radio duo were then told Prince William, 30, had left at 9pm and they could visit “any time after 9am”.

Christian told listeners: “If this has worked it is the easiest prank we have ever made.”

Yesterday, hospital bosses launched an investigation.

Chief executive John Lofthouse slammed the outrageous stunt as “a foolish prank call that we all deplore”.

He added: “We take patient confidentiality extremely seriously and we are reviewing our phone protocols.”

Meanwhile, angry royal fans took to Twitter to voice their outrage.

Rachel Hawkes tweeted: “Shame on you... you make me embarrassed to be Australian.”

Radio duo Greig and Christian, who appear on Aussie station 2Day FM, later released an apology, saying: “We thought we’d be hung up on as soon as they heard our terrible accents.

“We’re very sorry if we’ve caused any issues and we’re glad to hear that Kate is doing well.”

The prank call is said to have left royal officials seething. The Queen’s former Press Secretary Dickie Arbiter said: “This is a shocking breach of security.

“The Royal Family have been clients of the hospital for many, many years. It beggars belief that a member of the public could call up and obtain details of the Duchess’s medical condition.”

Kate is set to remain in hospital for the next few days.

A prayer for Kate and Wills was published by the Church of England yesterday for people to use at services.

It is available on their website, and reads: “God our creator, we thank you for the wonder of new life and for the mystery of human love. We pray for William, Duke of Cambridge, and Catherine, Duchess of Cambridge, as they prepare to receive the gift of their child.”